The aim of this project is to develop a novel 'liquid array' platform, based on Encoded Sortable Particle (ESP) technology. ESPs are optically-encoded microfabricated particles that can be manipulated using magnetic force. They are manufactured on commercially available photolithographic equipment, using efficient and robust techniques borrowed from the semiconductor industry. They have significant advantages in cost, throughput, scalability, and flexibility over existing bead-based liquid array platforms. We will develop a liquid array system that can accommodate multiplexing levels of 1,000-plex or more, and that will be more flexible and easier to use than existing systems. Its design will also permit substantially lower capital and running costs and similar or better quantitative performance, including precision, limit of detection and dynamic range. The ESP technology will provide a broad platform for many different kinds of assays. It is intrinsically versatile, and has the potential to be used in basic biomedical research, as well as high-throughput discovery and clinical diagnostics. The ability to control the particles magnetically is a significant advantage. The technology has the potential to be useful in basic research, diagnosis and prognosis of cancer, and a wide variety of other diseases.